Cancer remains a significant burden on society despite decades of research and prevention programs. In the United States alone there will likely be over 1,658,370 new cases of cancer diagnosed in 2015, with an estimated 589,430 dying from the disease. The National Cancer Institute estimates that today over 13 million people in the U.S. are living with cancer. Metastasis typically describes the disease progression where cancer cells originating from the primary tumor spread via several pathways to other organs in the body, initiating new tumors. Greater than 90% of the deaths related to cancer are due to the metastatic processes within cancer.
The National Comprehensive Cancer Network® (NCCN®), a not-for-profit alliance of 23 of the world's leading cancer centers devoted to patient care, research, and education, is dedicated to improving the quality, effectiveness, and efficiency of cancer care. NCCN® updates and publishes clinical practice guidelines, describing recommended treatment protocols appropriate for use by patients, clinicians, and other health care decision-makers. Even today, current NCCN® guidelines frequently classify cancers based on the anatomical site where the primary tumor has been identified, as has been the case historically. Any changes to the NCCN® guidelines typically require extensive clinical evidence demonstrating significant improvement in patient outcomes. Unfortunately, generating that level of evidence typically requires years and for many cancer patients, time runs out.
Genetic sequencing of the tumor cells has the potential to revolutionize how cancer is treated. Cancer therapy within the past several years has seen advances in the use of Next Generation Sequencing (NGS) to characterize tumors in order to identify specific genetic mutations that help to may identify responders to new or existing targeted therapies. However, cancer research has recently begun to illustrate that not all tumor cells within a primary tumor site are identical. Indeed, it is known that up to 69% of somatic mutations cannot be detected across all regions within a tumor. The implications from such findings immediately pose an important therapy treatment question regarding the use of NGS on patient tumor specimen, namely: which cancer cell(s) should be genetically analyzed to reveal the significant driver mutations resulting in cancer metastasis? Perhaps the best answer would be to identify the set of cancer cells most likely to be involved with tumor metastasis, which ultimately causes the vast majority of patient deaths due to cancer.
An increasing body of evidence has recently appeared in the scientific literature suggesting the existence of cancer stem cells (CSCs). This research indicates that a rare subset of cancer cells may be responsible for the initiation of tumors outside and away from the primary tumor. More recent scientific evidence is beginning to suggest that traditional, non-targeted chemotherapy may actually be increasing the number of CSCs, which may explain a resurgence of the disease in numerous patients following initial chemotherapy success. Clearly, additional approaches are needed to better treat cancer.